Integrated computer module

ABSTRACT

The invention is an integrated computer module (ICM) for connection to a host connector means in a host assembly that has a DC voltage supply and that is connected to or contains a display. The ICM uniquely includes an EMI enclosure, a fan, a computing subsystem, and a module connector. In more detail, the computing subsystem includes a microprocessor, a hard disk drive for storing an operating system, a main memory array, a video memory array for storing digital display descriptor data in a video memory array; and a video controller for converting the digital display descriptor data to a time-based display data stream suitable for driving the display. The host connector, moreover, includes first conductors for coupling the time-based display data stream to the display via the host connector means; second conductors for receiving the DC voltage from the DC voltage supply in the host assembly via the host connector means to power the computing subsystem; and third conductors for exchanging data with an I/O device via the host connector means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to integrated computer modules and, morespecifically, to an integrated computer module that contains thecomputing system components that are most prone to obsolescence andoften suitable for simultaneous replacement, including a CPU, mainmemory, a disk drive and a video controller.

2. Description of the Related Art

Today's personal computers (PC's) are usually sold in a desktopconfiguration or a notebook configuration. Desktop PC's are generallyhoused in a relatively large chassis containing a main printed circuitboard or “motherboard” and other components that are incorporated intoor connected to the motherboard. The components may be located inside oroutside of the chassis. Typical internal components include a powersupply, a central processing unit (CPU), random access memory (RAM), amass storage device such as a magnetic disk drive, expansion cardsconnected to a bus on the motherboard, and various peripherals mountedon “rails” in “bays” within the chassis and electrically connected tothe motherboard or an associated expansion card by a ribbon cable or thelike. Typical expansion cards are a SCSI adapter, a sound adapter, and anetwork adapter. Typical bay-mounted peripherals are a magnetic diskdrive, a floppy drive, a tape drive or a CD-ROM drive. Typical external“peripherals” include user input devices such as a keyboard, a mouse, amicrophone, a joystick, a graphics tablet or a scanner and user outputdevices such as speakers a printer, and a video display device (e.g. aCRT display or an LCD display). The video adapter that controls thedisplay, as with other adapters, may be integrated into the motherboardor provided on a separate expansion card.

The users of desktop PC's may be divided into two divergent groups: (1)experienced users who understand the individual components and tend tofrequently upgrade their PC's by replacing such components, and (2) newusers who do not understand or even want to understand the individualcomponents. The latter group may prefer to replace the entire PC, ifthey upgrade at all. With respect to both groups, however, it has beenobserved that the need or desire to upgrade occurs far sooner withrespect to some components than with respect to other components. Inparticular, users more frequently upgrade the CPU, the RAM, the magneticdisk drive, and the video adapter. These upgrades tend to provide morecapacity and more speed because of rapid technological advancements onthe part of manufacturers in response to ever-increasing demands fromever more complicated and more graphics intensive software applicationsand an associated increase in file sizes. Both user-types lessfrequently need or desire to upgrade the monitor, the speakers, thekeyboard or the power supply, however, because these latter componentshave withstood the test of time and employ technologies that are lessprone to obsolescence.

These inventors expect that the computer paradigm will move from a largechassis full of individual components of different manufacture toward areadily upgraded system consisting of two primary components: (1) anintegrated computer module that compactly houses the frequently upgradedcomponents (e.g. the CPU, the memory, the disk drive, and the videoadapter) and provides a module connector for interfacing the module'selectronics with peripherals, and (2) a “host assembly” with a dockingbay that receives the module and provides a host connector that mateswith the module connector. The host assembly can comprise any “shell”that includes the bay that receives the integrated computer module. Thedocking bay may be in a host assembly that doubles as a peripheral or inan intermediate assembly that is connected to conventional peripherals.The host assembly, for example, may function and appear generally like aconventional CRT display, save for the addition of the docking bay. ACRT-like host assembly of this nature would also provide a firstconnector for receiving input from a keyboard and, in all likelihood, asecond connector for receiving input from a mouse. As another example,the host assembly may appear like a conventional tower chassis thatcontains a docking bay for receiving the module, and suitableelectronics (e.g. a printed circuit board or PCB, cables, and so on) tointerface the integrated computer module to conventional expansion cardsvia an expansion bus, and to conventional peripherals like a display, akeyboard, and a mouse, via connector ports built-in to the host assemblyor carried by an expansion card.

There are a number of challenges associated with packing computercomponents and storage capability into a small integrated computermodule. One such challenge is maintaining safe operating temperaturesgiven a microprocessor and other components that dissipate relativelyhigh levels of power. Another challenge for designing and building suchmodules is providing adequate shock protection for sensitive structureslike disk drives. Still another challenge is providing an arrangement ofcomponents which allows for cost effective manufacturing processes. Yetanother challenge is making sure the module is not abruptly removed fromthe host assembly during data-critical operations.

Computer modules and associated bays have already been proposed. Forexample, in U.S. Pat. No. 5,463,742 that issued in 1995 to Kobayashi,assigned to Hitachi, the inventor discloses a “personal processormodule” (PPM) that fits within a notebook type docking station or adesktop type docking station, or simply attaches to a docking housing 6that is cabled to a keyboard and a monitor. (See FIG. 1). As shown inFIG. 2, however, the '742 Patent discloses a PPM 2 which communicateswith a docking station 3 via a pair of physical connectors 22, 24 thatconnect a local bus 20 in the PPM 2 with a local bus 33 in the dockingstation 3. As shown, therefore, the graphical adapter 48 is necessarilyprovided in the docking station 3 rather than the PPM 2.

As noted above, the user often needs or desires to upgrade the videocontroller at the same time that the user upgrades the CPU, the memory,and the disk drive. If the user of a PPM constructed according to the'742 patent upgraded to a newer PPM, however, the user would have tocontinue using the older graphical adapter 48, unless the user went tothe trouble and inconvenience of separately updating the graphicaladapter 48 or replacing the docking station 3 altogether.

There remains a need, therefore, for an integrated computer module thatcontains the computing subsystem components that are most prone toobsolescence and often suitable for simultaneous replacement.

SUMMARY OF THE INVENTION

In a first aspect, the invention may be regarded as an integratedcomputer module (ICM) for connection to a host connector means in a hostassembly, the host assembly containing a DC power supply with DC voltagetherefrom coupled to the host connector means, the host assemblyconnected to or containing a display, the ICM comprising: a computingsubsystem operable solely when connected to the host assembly, thecomputing subsystem further comprising: a microprocessor; a hard diskdrive for storing an operating system; means for supporting a mainmemory array; means for transferring at least a portion of the operatingsystem to the main memory array; means for coupling the microprocessorto the main memory array for executing the operating system; means forstoring digital display descriptor data in a video memory array; and avideo controller for converting the digital display descriptor data to atime-based display data stream suitable for driving the display; moduleconnector means for connecting to the host connector means, the moduleconnector including first conductors for coupling the time-based displaydata stream to the display via the host connector means; secondconductors for receiving the DC voltage from the DC voltage supply inthe host assembly via the host connector means to power the computingsubsystem; and third conductors for exchanging data with an I/O devicevia the host connector means; an EMI enclosure for containing emissionsfrom the computing subsystem; and a fan powered by the DC voltagereceived via the host connector means for providing airflow to maintainthe microprocessor within specified thermal limits.

BRIEF DESCRIPTION OF THE DRAWINGS

The just summarized invention may best be understood with reference tothe Figures of which:

FIG. 1 is a perspective view of an integrated computer module (ICM) thatmay be used with a host assembly according to this invention;

FIG. 2 is a perspective view of a chassis weldment that is formed as aopen-top “tub” into which the components of the ICM are assembled;

FIG. 3 is a top plan view of the tub of FIG. 2 showing how it is dividedinto sub-compartments, including a memory compartment 31, a coolingcompartment 32, and a drive compartment 33;

FIG. 4 is an exploded view of the integrated computer module of FIG. 1,showing the components which are assembled into the tub of FIG. 2;

FIG. 5 is a flow chart setting forth the steps of a first method ofassembling an integrated computer module beginning with a tub ingeneral;

FIG. 6 is a flow chart setting forth the steps of a second method ofassembling an integrated computer module beginning with the tub of FIG.2;

FIG. 7 shows a partially assembled integrated computer module withemphasis on the intermediate plate and its interconnection to the tub;

FIG. 8 is an exploded view of the integrated computer module of FIG. 7;

FIG. 9 is a cross-sectional view of the ICM of FIG. 1 (with the coverremoved and the PCM card absent) showing a preferred cooling tunnel forefficiently cooling the ICM's microprocessor;

FIG. 10 is a simplified schematic view of the cooling tunnel of FIG. 9;

FIG. 11 is a further simplified view of the cooling tunnel of FIG. 9with emphasis on the tapering section which accelerates cooling air intothe tunnel;

FIG. 12 is a rear view of the integrated computer module of FIG. 1;

FIG. 13 is a section view of FIG. 12 taken along section lines 13—13;

FIG. 14 is a block diagram of the system architecture of a computingsubsystem used in an ICM according to this invention;

FIG. 15 is a rear perspective view of a host assembly that contains aCRT display and is configured to appear like a conventional CRT monitor;

FIG. 16 is a front perspective view of a host assembly configured toappear like a conventional tower chassis that may be connected to amonitor, a keyboard, and a mouse (not shown);

FIG. 17 is a generalized cutaway view of a docking bay according to thisinvention, suitable for use in a host assembly like those illustrated inFIGS. 15 and 16 and configured to receive, electrically mate with, andretain an integrated computer module like the one shown in FIG. 1;

FIG. 18 is a cutaway plan view of the integrated computer modulepartially inserted into a host assembly to illustrate engagement withthe projecting member;

FIG. 19 is an elevational view of an adapter PCB for transforming astandard 5¼ peripheral bay of a conventional chassis into a docking bayaccording to this invention;

FIG. 20 is a side view of the adapter PCB of FIG. 19 and an associatedadapter sleeve that is externally sized for insertion into a standard 5¼drive bay and is internally sized for receiving an integrated computermodule like the one shown in FIG. 1;

FIG. 21 is a top view of the adapter sleeve of FIG. 20;

FIG. 22 is a rear view of the adapter sleeve of FIG. 20; and

FIG. 23 is a side view of a preferred bay configuration (shown here inconnection with an adapter sleeve) wherein the host connector isincorporated into the edge of a main host PCB;

FIGS. 24 is a perspective view of the preferred locking mechanism;

FIG. 25 is an exploded view of the locking mechanism of FIG. 24;

FIG. 26 is a partial cutaway view of the locking mechanism of FIG. 24 assituated in an ICM;

FIG. 27 is a partial cutaway view of the locking mechanism of FIG. 24after having engaged a projecting member extending from the back of thedocking bay;

FIG. 28 is a schematic of a preferred control circuit for operating thelocking mechanism of FIG. 24;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A. The Integrated Computer Module

A.1. Generally

FIG. 1 shows an integrated computer module (ICM) 100 that may be used ina host assembly having a docking bay according to this invention. From astructural point of view, the ICM 100 generally comprises a metalenclosure (not shown in FIG. 1, but see FIG. 4) that may beaesthetically surrounded by a case comprising, for example, a sleeve 180and an associated bezel or faceplate 181. The preferred faceplate 181includes cooling apertures 186 and a handle 182 for carrying the ICM 100and for pushing or pulling the ICM 100 into or out of a docking bay (notshown in FIG. 1). The preferred sleeve 180 includes at least one keyfeature such as chamfered edge 189 that mates with a corresponding keyfeature in the docking bay. In the example shown, key feature 189comprises a chamfered edge along one corner of the substantiallyrectangular periphery of the sleeve 180 which mates with a correspondingchamfered corner 389 (shown in FIGS. 15, 16) of the docking bay. Thesleeve 180 and faceplate 181 are preferably injection molded componentsmade of any suitable material such as ABS, PVC, or engineered plastics.

The preferred ICM 100 of FIG. 1 also includes an aperture 184 in thefaceplate 181 for exposing an optional PCI Mezzanine (PCM) card 160 thatprovides additional functionality such as an ethernet port, a SCSI port,or other desired function. A blank PCM cover plate (not shown) may belocated in the aperture 184 in the absence of a PCM card 160.

Referring to FIGS. 2, 3 and 4, the construction of the preferred ICM 100can be ascertained. FIG. 2 is a perspective view of a chassis weldmentformed as an open-top “tub” 110 into which the components of the ICM 100are assembled. FIG. 3 is a top plan view of the tub of FIG. 2 showinghow it is divided into sub-compartments, including a memory compartment31, a cooling compartment 32, and a drive compartment 33. Finally, FIG.4 is an exploded view of the ICM 100, showing the presently preferredconstruction in more detail. As shown in FIG. 4 and discussed in moredetail below, the ICM 100 is designed so that it can be assembled byhand or more efficiently, and more cost effectively assembled usingautomated assembly techniques. In particular, the components of thepreferred ICM 100 are generally assembled, from above, into the open-toptub 110. The preferred ICM 100, in other words, is assembled in asuccessively stacked, layer by layer arrangement as suggested by theprocess flow charts of FIGS. 5 and 6. The tub 110 and all of thecomponents inserted therein are ultimately covered with a ceiling wall119 and then, if appropriate for the desired application, enclosed inthe sleeve 180 and faceplate 181 that form the outer case shown in FIG.1. The preferred ceiling wall 119 makes a snap-on connection to the tub110 to speed assembly and eliminate the necessity for any threadedfasteners or the like.

Returning to FIGS. 2 and 4, the tub 110 has a floor wall 111, a frontwall 112, a back wall 113 opposite the front wall, a first side wall114, and a second side wall 115 opposite the first side wall. In orderto define a space sized for receiving a disk drive 130, an intermediateside wall 116 is also provided between the first side wall 114 and thesecond side wall 115 and an intermediate front wall 50 is providedbetween the back wall 113 and the front wall 112. The tub 110 furtherincludes a fan bracket 40 which receives a cooling fan, and a pluralityof front and rear cooling apertures indicated at 107, 109 in the frontand back walls respectively for passage of cooling air. A hold-down ramp47 extends from the bottom of the fan bracket 40 for airflow reasons asdiscussed below. The tub 110 is designed to minimize leakage ofelectromagnetic interference (EMI) in accordance with FCC requirements.Accordingly, the tub 110 and associated ceiling wall 119 are metallicand the cooling apertures 107, 109 are sized and configured to meet thedesired EMI requirements at the frequencies of interest.

The ICM's internal components generally include a shock mount system120, a disk drive 130 that is supported in the shock mount system 120and may have a controller PCBA 131 mounted on one side thereof, anintermediate plate 140, a main PCBA 150, and an optional PCM expansioncard 160 as mentioned above. Preferably, the main PCBA 150 includes amicroprocessor such as an Intel Pentium (not shown) located beneath asuitable heat sink 153, first and second memory module connectors 156for holding memory modules 157 of a suitable type and desired capacity(e.g. Single Inline Memory Modules, or Dual Inline Memory Modules), anda module connector 154 for interfacing the overall ICM 100 to a hostassembly. Collectively, the components mounted on the main PCBA 150comprise substantially all the circuits needed for a computingsubsystem.

As the ICM 100 contains volatile memory 157 and a disk drive 130, therecould be a catastrophic loss of data if the ICM 100 were inadvertentlyremoved before data stored in memory is saved to disk or during a writeoperation. As shown in FIG. 4, therefore, the preferred ICM 100 includesa locking mechanism 190 for preventing data corruption or loss due to asurprise removal of the ICM 100. The preferred locking mechanism 190engages a projecting member 280 shown in FIG. 18 (discussed below) inthe docking bay as discussed below. The preferred locking mechanism 190mechanically snaps into a corner of the tub 110 between an upper slot118 and a lower slot (not shown).

Returning to FIG. 5, taken in view of the structures discussed above,one can readily understand the preferred method of assembling an ICM100. In particular, one can appreciate that the assembly processproceeds by successively depositing components into the tub 110 fromabove. This approach makes the ICM 100 especially practical tomanufacture using automated assembly equipment, but efficiencies in handassembly are also made possible. The first step 401 in assembling an ICM100 according to this invention is providing a tub 110 having a floorwall 111, a front wall 112, a back wall 113 opposite the front wall, afirst side wall 114, and a second side wall 115 opposite the first sidewall. As defined here, the tub 110 may have one main compartment or mayhave a plurality of sub-compartment as shown in FIG. 3. The next step402 is depositing a lower shock mount (e.g. corner pieces 126) into thetub 110 and onto the floor wall 111. At step 403, a disk drive 130 isdeposited into the tub 110 with a lower side of the disk drive engagingthe lower shock mount. In next step 404, an upper shock mount (e.g.buttons 146) is deposited into the tub 110 so as to engage an upper sideof the disk drive 130, and at step 405 an intermediate plate 140 isdeposited into the tub 110 and onto the upper shock mount. The uppershock mount may be pre-bonded to an under side of the intermediate plate140 such that steps 404 and 405 occurs nearly simultaneously, butsuccessively. In step 406, the intermediate plate 140 is secured abovethe disk drive (i.e. to the tub 110) to retain the disk drive within thetub 110 between the upper and lower shock mount assemblies. In step 407,the main PCBA 150 is assembled into the tub and onto the intermediateplate 140. Step 408 involves making an electrical connection between themain PCBA 150 and the disk drive 130. In step 408, the process proceedsin step 409 by locating a module connector, electrically connected tothe main PCBA 150, at a desired location at the tub's back wall 113 toprovide for connection with a host connector when the ICM 100 isinserted into a host assembly. Finally, the process proceeds to step 410by depositing a ceiling wall 119 onto the tub 110 to define an enclosurethat contains the shock mount assemblies, the disk drive, theintermediate plate, and the main PCBA.

FIG. 6 is directed to an assembly process that is similar to thatillustrated by FIG. 5. Here, however, the process is directedspecifically to a tub 110 having a plurality of sub-compartments 31, 32,33 as shown in FIG. 3. The sub-compartments 31, 32, 33 are defined byproviding an intermediate side wall 116 and an intermediate front wall50 within the tub 110. The sub-compartments include a side compartment31 which provides space for receiving the memory modules extendingdownwardly from an underside of the main PCBA (not shown, but see FIG.4), and a drive compartment 33 for containing the disk drive 130. Alsoprovided is a front compartment 32 which provides an area foraccelerating cooling air from the fan over the main PCBA.

The assembly process of FIG. 6 comprises the steps of providing a tub110, as defined before, but now recites an area above the floor wallwhich includes a drive space 33 for containing the disk drive 130 and aside space 31 for containing a memory module. A front space 32, as shownin FIG. 3, is also contemplated. The spaces 31, 32, 33 are preferablyformed with intermediate walls 116, 60, but they may be less clearlybounded as through the use of small drive retention brackets or thelike. The tub 110, as noted above, includes front and back coolingapertures 107, 109. It may be desirable, therefore, to include a fanbracket 40 adjacent the front cooling apertures 107 for convenientlyreceiving a fan 170 deposited from above. The assembly process of FIG. 6comprises the further steps of depositing a lower shock mount (e.g.corner pieces 126) into the tub's drive space 33 and onto the floor wall111 (step 503); depositing a disk drive 130 into the tub's drive space33 with a lower side of the disk drive engaging the lower shock mount(step 504); depositing an upper shock mount (e.g. buttons 146) into thetub's drive space 33 so as to engage an upper side of the disk drive 130(step 505); depositing an intermediate plate 140 into the tub 110 andonto the upper shock mount (step 506); securing the intermediate plateabove the drive space to hold the disk drive 130 within the tub's drivespace 33 between the upper and lower shock mounts (step 507); depositinga main PCBA 150 into the tub and onto the intermediate plate 140, themain PCBA including a portion which extends over the side space 31 andis adapted to support a memory module extending downwardly therefrom(step 508); electrically connecting the main PCBA 150 to the disk drive130 (step 509); locating a module connector, electrically connected tothe main PCBA 150, at a desired location at the tub's back wall 113 toprovide for connection with a host connector when the ICM 100 isinserted into a host assembly (step 510); and finally depositing aceiling wall 119 onto the tub 110 to define an enclosure that containsthe lower shock mount, the disk drive, the upper shock mount, theintermediate plate, and the main PCBA (step 512).

In a final assembly process, one that is optional, the tub 110 and itsinterior components are encased in the sleeve 180 and the associatedfaceplate 181. As the faceplate 181 includes a handle 182 for carryingthe entire ICM, it is important that the faceplate 181 have a secure,mechanical connection to the tub 110. The presently preferredconstruction for such a positive, mechanical connection comprises twopairs of backwardly-extending fingers 187 having inwardly extendingdetents (not shown), one pair on each side of the faceplate 181, and twocorresponding pairs of slots 117 on the first and second side walls 114,115 of the tub 110. As suggested by FIG. 4, the faceplate 181 isinitially pressed onto the tub 110 until the detents on its fingers 187engage the slots 117. Next, the tub 110 is inserted into the sleeve 180,the sleeve 180 thereby encasing the tub 110 and the fingers 187 so thatthey cannot splay outward and disengage from the slots 117. The sleeve180 itself include an upper finger 185 and a lower finger (not shown),each having ramp-shaped projections that engage upper and lower ridgeson the faceplate 181.

Referring once more to FIG. 4, the preferred shock mount system 120comprises a lower shock mount and an upper shock mount that arepreferably comprised, respectively, of four corner pieces 126 and fourbuttons 146 that are each formed from an elastomeric material, thepreferred material being Sorbathane sold by Sorbathane, Inc. The cornerpieces 126 each have a base and two intersecting, substantiallyperpendicular walls (not separately numbered) extending upwardly fromthe base (not separately numbered). During assembly, the corner pieces126 are simply located with their bases on the floor wall 111 of the tub110, and with their upstanding walls in the corners defined by the frontwall 112, the back wall 113, the first side wall 114, and theintermediate wall 116. The upstanding walls of the corner pieces 126 aresized to provide a firm press fit relationship when compressed betweenthe disk drive 130 and the surrounding walls 50, 113, 114, 116. The fourbutton 146 are placed in wells (not shown) formed in the intermediateplate 140 to capture an opposite side of the disk drive 130 as describedfurther below.

The presently preferred shock mounting system 120 requires us to orientthe disk drive 130 with its controller board 131 facing upward, i.e. ina “board-up” orientation. The board-up orientation is preferred becauseit places the controller board 131 as close as possible to the main PCBA150, thereby allowing a short cable with minimal signal degradation. Ashort cable is becoming increasingly important with higher data rates.In fact, given the ever increasing power of CPU's, it is now possible tocontrol the disk drive via an ordinary expansion bus, such as the PCIbus, where a short cable may be critical. The board-up orientation isalso preferred because the shock mounts 126 will not block access to theconnectors 132 that are on the controller board 131. It is alsodesirable to mount the disk drive 130 board-up because the other side ofthe disk drive presents a clean, solid volume for contact with the shockmount system 120.

The disk drive 130, therefore, is oriented board side up and thenpressed down onto and in between the four corner pieces. Next, theintermediate plate 140 is secured in the tub 110, between the first sidewall 114 and an intermediate wall 116, to firmly hold the disk drive 130downward on the corner pieces 126. The intermediate plate 140 ispreferably secured with tabs on one side and snap-fit fingers on theother side, but the plate may be suitably secured with conventionalthreaded fasteners, or the like. Note that the controller board 131 isrecessed into the disk drive's aluminum casting 132, leaving a pair ofelongated casting rails 133 extending up above the board 131. The uppershock mounts (elastomeric buttons) 146 are preferably bonded to theintermediate plate 140, but they may be placed onto the casting rails inadvance of securing the intermediate plate 140, without bonding,particularly if the upper shock mounts are provided in an alternativecorner-shaped or L-shaped geometry that is unlikely to move during theassembly process. The buttons 146 press down against the elongated rails133 of the casting 132. Consequently, the buttons 146 isolate theintermediate plate 140 from the rails 133, thereby enabling the shockmount system 120 to mechanically couple the disk drive 130 to the tub110 via a shock-isolating, elastomeric interface.

The intermediate plate 140 also protects the disk drive's controllerboard 131 from electromagnetic interference (EMI) emanating from themain PCBA 150. The main PCBA 150 transmits significant amounts of RFenergy over a wide frequency spectrum because it has synchronouslyclocked components that operate at relatively high power levels (e.g.greater than 5 watts) and at a plurality of relatively high clockfrequencies (e.g. 66 MHz, 100 MHz, 500 MHz, and so on). The disk drive'scontroller PCBA 131, on the other hand, contains circuitry that operatesat relatively low millivolt levels that are associated with reading andwriting data to and from the disk drive 130. The intermediate plate 140,therefore, beneficially functions as an EMI shield in addition tosecuring the disk drive 130 in the tub 110. The preferred plate 140 ismade of the same metallic material as the remainder of the tub 110 sothat it represents an intermediate ground plane that tends to arrestconducted and radiated RF energy.

FIG. 7 shows the intermediate plate 140 and its interconnection to thetub 110 in more detail. As shown therein, the intermediate plate 140 hasa central section, a front edge, a back edge opposite the front edge, afirst side edge, and a second side edge opposite the first side edge.The preferred intermediate plate 140 has a pair of tabs 141 on its firstside edge which interface with a corresponding pair of slots (notnumbered) in the first side wall 114. The second side of the plateincludes a pair of downwardly-extending fingers 143 that mate with oneside of the intermediate wall 116 and an elongated lip 144 that mateswith an opposite side of the intermediate wall 116. Thedownwardly-extending fingers 143 have detents (see FIG. 8) which matewith slots (not shown) in the intermediate wall 116.

FIG. 8 is an exploded view of FIG. 7 showing the preferredinterconnection between the intermediate plate 140 and the disk drive130 in the tub 110. As shown, the intermediate plate 140 does not makedirect contact with the disk drive 130. Instead, four upper shock mounts146 are bonded or otherwise attached to corresponding wells 145 in theintermediate plate 140. The disk drive 130, therefore, is encased andelastomerically supported between the tub 110 and the intermediate plate140 by the lower shock mounts 126 (see FIG. 4) and the upper shockmounts 146.

As best shown in FIG. 4, the main PCBA 150 is secured in the tub 110above the intermediate plate 140. In the presently preferred embodiment,the main PCBA 150 is secured with two screws (not shown) that passdownward through two apertures—a central aperture 155 and a sideaperture 159. The central screw mates with a threaded aperture in thetop of a standoff (not shown) that has a threaded fastener that extendsfrom its bottom and is screwed into a threaded boss 147 (see FIG. 8) inthe center of the intermediate plate 140. The side screw mates with athreaded aperture in the top of a similar standoff (also not shown) thatscrews into a threaded aperture located at one end of a shelf bracketshown in FIG. 7 that is welded to the second side wall 115 of the tub110. The other end of the preferred shelf bracket has outwardlyextending, vertically spaced fingers (not shown) that surround the topand bottom of the main PCBA 150 and thereby secure it at a thirdlocation. It is important, of course, to ground the main PCBA 150. Thepreferred standoffs are conductive and make contact with correspondingtraces that surround the main PCBA's central and side apertures toprovide such grounding.

The main PCBA 150 may be divided into two upper portions and two lowerportions. The upper left half of the main PCBA 150 carries the CPU andits heat sink 153. The upper right half carries a standard pair of PCMconnectors 158 for interfacing the PCBA 150 with any PCM expansion card160 that may be present. The majority left portion of the lower side ofthe main PCBA 150 rests closely against the intermediate plate 140 viasupport tabs 142 located to either side thereof and via a conductivestandoff located near the plate's center (not shown). This portion ofthe PCBA's underside may carry some low-profile components, but it doesnot have any extending components due to its close proximity to theintermediate plate 140. The minority right portion of the main PCBA'sunderside, however, carries a pair of memory sockets 156 that support apair of memory modules 157 which extend downwardly therefrom next to thedisk drive 130, in-between the intermediate wall 116 and the second sidewall 115. The ICM 100 may, of course, be provided with only one socket156 and one memory module 157. An aperture (not shown) and associatedcover plate 161 are provided on the tub's floor wall 111 and alignedwith the memory modules 157 to provide access to the modules after theICM 100 has been assembled.

The provision of highly efficient cooling is important because of thehigh power dissipation and component density in the relatively lowvolume of the ICM 100. Modern CPUs dissipate a significant amount ofheat. For example, an Intel Pentium III processor operating at 500 MHzwith a 512K L2 cache dissipates about 28 watts. The safe dissipation ofthis much heat requires a large, highly efficient heat sink 153, thepreferred heat sink being fabricated from aluminum because aluminumoffers a good compromise between heat dissipation and cost. The safedissipation of this much heat also requires that cooling air pass overthe heat sink's cooling fins (not numbered) at relatively high velocity,requiring at least 300 linear feet per minute (LFM). The air velocity atthe heat sink is, of course, a function of the fan's volumetric outputrate, the area of its exit aperture, and any leakage or airflowresistance that may be present. Chassis mounted cooling fans areavailable with airflow rates exceeding 200 cubic feet per minute (CFM).Given the advent of higher power CPU's and the endless variety ofchassis designs, chassis mounted fans are sometimes supplemented bydedicated CPU fans. Dedicated CPU fans guarantee adequate air flow overthe CPU. Because of their immediate proximity to the component to becooled, they tend to have lower airflow rates of 5 to 15 CFM.Considering both of these fan variants as a group, the cooling fan usedin the typical PC has an airflow rate from about 5 to 200 CFM. In eithercase, the larger, more powerful fans that provide the highest air volumeare generally more costly and louder than their less capablecounterparts.

If the cooling fans being considered for use push cooling air out anexit aperture with an area of about 6 square inches or about 0.04 squarefeet, and assuming a range of 5 to 50 CFM, the available cooling fansprovides a corresponding linear velocity of 125 to 1,250 linear feet perminute (LFM) at the exit aperture. This is the measurement thattranslates to effective cooling of the heat sink 153. Given cost andnoise considerations, one would choose the lowest possible rate fan thatprovides the desired linear velocity. FIGS. 9-11 relate to a uniquecooling tunnel 70 and associated structure for accelerating cooling airwithin the cooling tunnel 70 to permit the ICM 100 to use a smaller,quieter, less costly fan than would otherwise be required as follows.

The ICM's built-in cooling fan 170 is preferably located next to thefront wall 112 of the tub 110, next to the front cooling apertures 107,so that it has access to a continuous supply of relatively cool air. Thefan 170, with the help of unique accelerating structure, moves airthrough the cooling tunnel 70, over the fins of the heat sink 153, witha velocity of greater than 300 linear feet per minute (LFM).

The preferred airflow structure is best shown in FIGS. 9, 10 and 11. Asshown therein, the main PCBA 150 is designed so that the CPU's heat sink153 extends upwardly into the “cooling tunnel” 70 located between thefront and rear cooling apertures 107, 109 in the tub's front and backwalls. The cooling fan 170 has an exit profile of a first area 71. Theaccelerating structure comprises a tapering means 72 for acceleratingthe air flowing from the fan's exit profile of first area 71 into thecooling tunnel 70 which has a tunnel profile of a second smaller area73. The velocity of the cooling air is thereby accelerated within thetapering means 72 until it enters the cooling tunnel 70 at maximumvelocity. The amount of acceleration is approximately determined by theratio between the first and second areas 71, 73. The “approximate”qualifier is appropriate with respect to the preferred embodimentbecause the cooling tunnel 70 and the tapering means 72 are built fromother components such that they are not completely airtight orcompletely smooth.

The cooling tunnel 70 could be an integral or discrete structure that isseparable from other ICM components. As just mentioned, however, thepreferred cooling tunnel 70 is formed from the physical arrangement ofseveral existing components. A bottom of the tunnel 70 is defined by theupper surface of the main PCBA 150. A top of the tunnel 70 is defined bythe ceiling wall 119. A first side of the tunnel 70 is defined by thetub's first sidewall 114. Finally, a second side of the tunnel 70 may bedefined by a special partition member 90. In this fashion, theaforementioned components form a cooling tunnel 70 that axiallysurrounds the CPU's heat sink 153. The partition member 90 may have anoptional diverter flap 91 which diverts some of the accelerated coolingair passing through the cooling tunnel 70 into other areas of the ICM100.

The tapering means 72 can also take on a number of arrangements. Thepreferred tapering means 72, however, is an air ramp 72 which tapersupward from a bottom of the fan 170 toward the main PCBA 150 as shown inFIGS. 9 and 10. The air ramp 72 may be an integral member. In thepreferred embodiment, however, the air ramp 72 comprises the flexibleconductive assembly 60 (e.g. ribbon cable) which connects the main PCBA150 to the disk drive 130. In more detail, a first end of the ribboncable 60 is connected to the main PCBA 150 and a second end of theribbon cable 60 is connected to the controller PCBA 131. Bothconnections are made adjacent the cooling fan's exit profile 71. Theribbon cable 60 is folded back between its first and second ends to forma folded portion 61 and the folded portion is held down near the coolingfan 170 such that an upper surface of the folded portion 61 extendsdownwardly from the main PCBA 150 toward a bottom of the cooling fan170. The ribbon cable 60 is preferably held down by a hold-down ramp 47which extends from the bottom of a fan bracket 40 welded into the tub110. The hold-down ramp 47 does not have to extend from the fan bracket40, but could instead extend from the tub 110 per se or extend from thefront drive wall 50.

FIG. 12 shows a rear view of a fully assembled ICM 100, the side thatinterfaces with a host assembly having a docking bay as describedfurther below. As shown, substantially all of the back wall 113 isexposed at a rear end of the sleeve 180 to provide access to the moduleconnector 154, the cooling apertures 109, and a module aperture 80.

FIG. 13 is a cross-sectional view of the preferred module aperture 80 inFIG. 12. In particular, FIG. 13 shows that the preferred module aperture80 has radius edges 81 having a depth “D” that is greater than a width“W” of an annular groove 282 contained in a projecting member 280. Wemake “D” greater than “W” to ensure that the module aperture 80 does notaccidentally hang up on the projecting member 280 as described morefully below in connection with the locking mechanism and the hostassembly. The preferred module aperture 80 is formed by stamping orpunching through the back wall 113.

A.2 System Architecture

FIG. 14 is a block diagram of the preferred system architecture of acomputing subsystem 700 in an ICM 100 according to this invention. Asshown, a module connector means 760 interfaces the subsystem 700 with ahost connector means in host assembly (not shown), thereby providing theICM 100 and its optional cooling fan 170 with DC power and exchangingvarious signals over suitable I/O interfaces. These I/O interfaces arefurther discussed below. The module connector means 760 and associatedhost connector means (not shown) may comprise the module connector 154and associated host connector 254 shown in FIG. 18, an edge connectorand associated edge slot, or any other suitable connectors or collectionof connectors.

As shown in FIG. 14, the computing subsystem 700 is operable solely whenconnected to the host assembly. The computing subsystem 700 is basedaround a central processing unit (CPU) 152 such as an Intel Pentiumprocessor, a hard disk drive 130 for storing an operating system andapplication programs, a main memory array 720 for storing and executingthe operating system and application programs, a video memory array 740for storing digital display descriptor data, and a video controller 730for converting the digital display descriptor data to a time-baseddisplay data stream suitable for driving a display. The video memoryarray 740 may be combined with the main memory array 720, or provided asa separate structure as shown.

The CPU 152 communicates with other system components at or near theCPU's internal clock speed via a processor bus 701 and a bus/memorycontroller 710. In addition to communicating directly with the CPU 152,the bus/memory controller 710 communicates with the main memory array720 via a memory bus 702, with the video controller 730 via a video bus703 (e.g. an Advanced Graphic Peripheral bus or AGP bus), and with anI/O controller 750 via a system expansion bus such as a PCI bus 704.

The bus/memory controller 710 and its associated buses 702, 703, 704provide means for supporting the main memory array 720, means fortransferring at least a portion of the operating system to the mainmemory array 720, means for coupling the microprocessor 152 to the mainmemory array 720 for executing the operating system, and means forstoring digital display descriptor data in the video memory array 740.The structural and operational details of the bus/memory controller 710and its associated buses 702, 703, 704 are omitted for the sake ofbrevity as they are well within the knowledge base of those of ordinaryskill in this field.

As shown in FIG. 14, the PCI bus 704 further interfaces the CPU 152 witha standard pair of PCM connectors 158 for connecting to an optional PCMexpansion card (not shown). The PCI bus 704 may later connect directlyto a PCI-based disk drive 135, in lieu of or in addition to theIDE-based drive 130. The PCI-based disk drive 135 is not presentlyimplemented, however, as suggested by the dashed lines.

The ICM 100 of FIG. 14 uniquely integrates four system-critical,computing subsystem components that are particularly prone toobsolescence, namely the CPU 152, the memory array 720, the disk drive130, and the video controller 730 and its associated video memory array740. The ICM 100 suitably houses these components in an EMI enclosurefor containing emissions from the computing subsystem. Moreover, inorder to receive power from and communicate with a host assembly, theICM's module connector means 760 includes first conductors 735, 736 forcoupling the video controller's time-based display data stream to ananalog CRT display (VGA), a digital flat panel display (FP), or both,second conductors 762 for receiving the DC voltage from the DC voltagesupply in the host assembly to power the computing subsystem, and thirdconductors 752, 753, 754, 755 for exchanging data with I/O devices,including “legacy” devices such as a keyboard, a mouse, a serial portdevice, a parallel port device. Finally, the preferred ICM 100 containsa fan 170 powered by the DC voltage received via the host connectormeans 760 for providing airflow to maintain the microprocessor 152within specified thermal limits.

The I/O controller 750 interfaces the CPU 152 with various I/O devicesover the third conductors 752, 753, 754, 755. The inventors presentlycontemplate an I/O controller 750 that implements an Integrated DriveElectronics (IDE) interface having a primary IDE channel P_IDE and asecondary IDE channel S_IDE, a Low Pin Count (LPC) interface accordingto Intel's LPC Interface Specification, an audio interface AC97 thatoperates according to Intel's Audio Codec '97 specification, and aUniversal Serial Bus (USB) interface that operates according to the USBSpecification, Rev. 1.0.

The selection of interface protocols for the third conductor set isparticularly suitable for allowing the IPC to be interfaced to a widevariety of host assembly I/O device configurations, including thosewhich may not be ordinarily considered “personal computer” variants.Such host assemblies include but are not limited to home and commercialcontrol systems, communication systems, vending systems, entertainmentsystems, storage systems and financial terminals.

The topology of the IDE interface is also unique. In particular, the I/Ocontroller 750 communicates with an IDE-based disk drive 130 containedinside of the ICM via the conductors 751 of the primary IDE channelP_IDE. The primary IDE channel P_IDE, therefore, remains inside of themodule 100. The conductors 752 associated with the secondary IDE channelS_IDE, however, are connected to the module connector means 760 forexchanging data with an optional IDE peripheral that is contained in orattached to the host assembly (not shown).

B. The Host Assembly—Generally

FIGS. 15 and 16 show two host assemblies 200A, 200B. Both assembliescontain a power supply (not shown) for providing power to the hostassembly and to the ICM 100 inserted therein. The first preferred hostassembly 200A of FIG. 15 contains a CRT display and is configured toappear like a conventional CRT monitor 201 A. The second preferred hostassembly 200B of FIG. 16 is configured to appear like a conventionalfull-height tower chassis 201 B that has a conventional disk drive bay320 and may be connected to a display, a keyboard, and a mouse (notshown). Other configurations are possible. These two are merelyillustrative examples.

The preferred host assembly provides a docking bay that defines a cavityfor receiving an ICM 100. It is possible, however, to provide a dockingmodule (not shown) that releasably connects an ICM 100 to other deviceswithout providing a cavity 310 per se.

The FIG. 15 host assembly 200A uses a “built-in” docking bay 300 andassociated cavity 310 having key feature 389 for mating with module keyfeature 189. In operation, the user inserts the ICM 100 of FIG. 1 intothe cavity 310 until the ICM's module connector 154 (see FIG. 12) mateswith a host connector 254 (shown in FIG. 17) at the rear of the cavity310.

The FIG. 16 host assembly 200B, on the other hand, uses a “retrofit”docking bay adapter 400 that fits in a standard disk drive bay 320 anddefines a cavity 410 having a host connector (not shown) and the keyfeature 389 for receiving an ICM 100. The cavity 410 in the retrofitadapter 400 also provides a host connector 254 (shown in FIG. 17) suchthat the user may insert the ICM 100 into the cavity 410.

C. The Host Assembly—Bay Details

FIG. 17 is a generalize cutaway view of a built-in docking bay 300 orretrofit adapter 400 according to this invention, the docking baysuitable for use in a host assembly 200A, 200B like those illustrated inFIGS. 15 and 16 and configured to receive, electrically mate with, andretain an ICM 100 like the one shown in FIG. 1.

The docking bay has a cavity 310 defined by a continuous periphery,preferably rectangular, extending from a front opening (not separatelynumbered) to a back end 313 opposite the front opening. The cavity 310may be regarded as having an insertion axis (arrow) that isperpendicular to the periphery. Two items of interest are located at theback end 313 of the cavity 310: a host connector 254 for mating with themodule connector 154 and a projecting member 280 for providing a datasecurity function and an alignment function.

The host connector 254 is located a particular XY (horizontal andvertical coordinate reference) connector location at the back end 313 ofthe cavity 310 so that it mates with the ICM's module connector 154located at the same XY connector location when the ICM 100 is insertedinto the cavity 310. The host connector 254 may be centered on the backend 313 of the cavity, but the XY connector location is preferablyasymmetric so that, in the absence of a key feature 189, mating onlyoccurs if the ICM 100 is in the “correct” orientation.

The projecting member 280 extends into the cavity 310 in parallel withthe insertion axis so that it may be received in a correspondingaperture 80 in the rear wall 113 of the ICM 100. The projecting member280 may be located at an asymmetric XY location at the back end 313 ofthe cavity to prevent the user from fully inserting an unkeyed ICM 100into the cavity 310 in the wrong orientation. In either case, thepreferred projecting member 280 is located at the lower right corner ofthe cavity's back end 313 so that the ICM 100 may conveniently receiveit near the ICM's second side 115 (see FIG. 4). Other locations arepossible.

If the ICM 100 and docking bay 300, 400 are keyed, then the projectingmember 280 will always mate with the aperture 80 in the rear wall 113 ofthe ICM 100. In this preferred embodiment, the projecting member 280provides a guiding function and a locking function, but it does notimpact the ICM 100 because misalignment is not possible.

In the case of an un-keyed ICM 100, however, alignment is not assured.If the un-keyed ICM 100 is inserted in the correct orientation where theconnectors 154, 254 are aligned for mating, then the projecting member280 is simply received by the module aperture 80 in the rear wall 113 ofthe ICM's tub 110 (see FIG. 4). If the un-keyed ICM 100 is insertedupside down, however, then a solid portion of the rear wall 113 willcontact the projecting member 280 before the ICM's rear wall 113contacts and potentially damages the host connector 254 and before thecavity's rear end 313 contacts and potentially damages the moduleconnector 154.

FIG. 18 shows the ICM 100 partially inserted into the docking bay 300,400. Note that the projecting member 280 extends beyond position “A,”i.e. beyond the farthest most point of the host connector 254. Thislength ensures that the projecting member 280 contacts the ICM's rearwall 113 before the host connector 254 contacts the rear wall 113 if theICM is inserted upside down.

The projecting member 280 also provides an alignment function that isbest understood with reference to FIGS. 17 and 18. As shown, thepreferred projecting member 280 has an annular taper at its tip 284 thatslidably mates with the radius edge 81 of the module aperture 80. Theradius edge 81 essentially defines an annular beveled recess that guidesthe module aperture 80 onto the projecting member 280, and therebyfurther aligns the overall ICM 100 for mating the module connector 154to the host connector 254. The projecting member 280 must extend beyondposition “A,” however, if it also to provide such an alignment functionin cooperation with the module aperture 80. As shown, in fact, thepreferred projecting member 280 extends beyond reference position “A” toa farther reference position “B” to ensure that the module aperture 80envelopes the projecting member 280 before the module connector 154begins to mate with the host connector 254. A benefit of this additionallength is that ICM 100 contacts the projecting member 280 well beforethe position that the ICM 100 ordinarily sits when mounted in the bay.Accordingly, the user is given very obvious feedback, both tactile andvisual, that the ICM 100 is not corrected situated.

Suitably, the preferred connectors 154, 254 themselves include furthercomplementary alignment features to ensure that a truly “blind”insertion is possible. A wide variety of cooperating connector stylesmay be used, including but not limited to, pin and socket types, cardedge types, and spring contact types.

Although not shown, the inventors contemplate an alternative embodimentof the ICM 100 that is secured to a host assembly in a semi-permanentarrangement. For cost reasons, the semi-permanent embodiment would omitthe sleeve 180 and associated faceplate 181 and would replace the blindmating connector 154 with a more cost effective PCBA edge connectorhaving conductive fingers plated with minimal amounts of gold.

FIGS. 17 and 18 also show that the projecting member 280 provides a dataintegrity feature in connection with the locking mechanism 190 containedinside of the ICM 100. The projecting member 280, in particular,includes a retention notch 282 located on the side thereof. Thepreferred retention notch 282 is provided in the form of an annulargroove 282 that encircles the entire projecting member 280 and thepreferred locking mechanism 190 includes a latch plate 560 that locksthe ICM 100 into the docking bay 300, 400 by engaging the projectingmember's annular groove 292.

The preferred projecting member 280 is made of a conductive material andis grounded so that it may serve as a means for managing ESD. It isgenerally desirable to discharge electrostatic energy through aresistance to reduce the magnitude of an associated current spike.Accordingly, the projecting member 280 itself may be comprised of amoderately conductive material such as carbon impregnated plastic or theprojecting member 280 may be made of a highly conductive material suchas metal and connected to ground through a discharge resistor as shownin FIG. 18. In either case, the desired resistance is about 1-10megohms.

FIGS. 19-22 show a presently preferred construction for a “retrofit”docking bay adapter 400 as might be used in the standard drive bay 230in the host assembly 200B of FIG. 16. As shown, the retrofit adapter 400comprises an adapter sleeve 420 and an adapter PCB 430 that is mountedto a back end of the adapter sleeve. The adapter sleeve 420 includes asuitable means for mounting to a standard drive bay 320 such as, forexample, a plurality of threaded mounting holes 421 that are sized andspaced to interface with screws and corresponding through holes 321 (seeFIG. 16) in a standard 5¼ drive bay 320. The preferred adapter sleeve420 is formed of injection molded plastic. It includes a number ofopenings 425, therefore, to reduce the required amount of plasticmaterial.

The adapter PCB 430, shown from the rear in FIG. 19 and from the side inFIG. 20, carries the host connector 254, the projecting member 280, andsuitable circuitry 434 for interfacing the adapter PCB 430 to othercomponents in the host adapter.

FIG. 23 is a side view of a preferred structure for supporting the hostconnector 254. Here, instead of being supported on a separate PCB 430 asin FIGS. 19 and 20, the host connector 254 is incorporated into the edgeof a main host PCB 250 in order to simply the construction and reducecosts. FIG. 23 shows such structure in connection with an adapter sleeve400, but is probably more applicable for use with a “custom” built-indocking bay 300 as used in a host assembly 200A like that shown in FIG.15, where more control can be exercised over the construction of themain host PCB 250 contained in the host assembly 200A.

D. The Locking Mechanism for Securing the ICM in the Host Assembly

FIGS. 2, 4 and 18 illustrate the preferred locking mechanism 190 to somedegree. Having already discussed the ICM 100 and host assembly 200A,however, it is now possible to focus on the details of the lockingmechanism 190 and its interface with the projecting member 280.

FIGS. 24 and 25 illustrate the construction of the preferred lockingmechanism 190 in isolation. FIG. 24 show the locking mechanism 190 in afully assembled state whereas FIG. 25 shows it in an exploded state. Asshown in both figures, the locking mechanism 190 generally comprises alatch body 510, a solenoid 540 with a frame 541, a coil 542, a plunger543, and a latch plate 560. The latch body 510 includes a back wall 511,a first side wall 512 extending from the back wall 511, a second sidewall 513 extending from an opposite side of the back wall 511, and apair of inwardly extending front walls 514, 515. The latch body'svarious walls 511, 512, 513, 514, 515 are configured to define an uppersolenoid chamber 520 and a lower latch plate chamber 530. In particular,the upper solenoid chamber 520 includes a pair of spaced-apart grippingmembers 521, 522 that engage the solenoid's frame 541 and the lowerlatch plate chamber 530 includes first and second grooves 531, 532 thatslidably receive the latch plate 560. FIGS. 24 and 25 also show theconnection between the solenoid plunger 543 and the latch plate 560. Asbest shown in FIG. 25, the latch plate 560 has retention tabs 564 thatengage a retention groove 544 in the plunger 543. The plunger 543 isbiased downward by an internal spring (not shown) or the like.Accordingly, the plunger 543 includes a stop ring 545 that ultimatelyrests on stop shoulder 519 to limit the plunger's downward travel.

FIGS. 26 and 27 are partial cutaway views that show the latch mechanism190 in its ultimate location near the back wall of the ICM 100. Assuggested by such figures, the locking mechanism 190 includes a lowertab 516 and an upper projection 517 which, as shown in FIGS. 2 and 4,provide a snap-in connection at a back corner of the tub 110 via anupper slot 118 and a lower slot (not shown).

FIG. 18, discussed earlier, shows the ICM 100 partially inserted intothe docking bay 300. FIG. 21 shows the locking mechanism 190 before ithas received the projecting member 280 and FIG. 27 shows the samemechanism 190 after it has received the projecting member 280. Inoperation, when the ICM 100 is inserted into the docking bay 300, thetip 284 of the projecting member 280 extends through the module aperture80 in the back wall 113 of the tub 110 (shown in FIGS. 12,13 and 18),through an aligned aperture 580 in the back wall 511 of the latch body510, and presses upwardly against a notch 568 in the latch plate 560.The latch plate 560 ultimately moves upward until the projectingmember's annular groove 282 is beneath notch 568 in the latch plate 560,at which point the latch plate 560 moves downward such that its notch568 securely engages the projecting member's annular groove 282 as shownin FIG. 27. The ICM 100, therefore, is mechanically retained in thedocking bay 300 until the solenoid 542 is energized to pull up theplunger 543 and associated latch plate 560 and thereby release theprojecting member 280.

FIG. 28 is a schematic of a preferred control circuit 600 for thelocking mechanism 190. The circuit 600 is designed so that the solenoid542 may be programmatically energized through transistor Q14 or manuallyenergized through switch SW1 on an “emergency” basis in the absence ofpower from the host assembly. In the presence of host assembly power,the solenoid 542 will be energized only if UNLATCH# and PWR_GD# are bothasserted (low). The UNLATCH# signal is software controlled such that itis programmatically asserted only when the probability of a falseassertion is remote (i.e. power is on and is good) and when it is safeto do so (e.g. in the absence of a writing operation.) The UNLATCH#signal is provided on an open-collector port in the preferredembodiment. Accordingly, the input to the AND gate U37A is pulled highthrough a resistor R267 so that the input is forced high during the timethat the UNLATCH# signal is not asserted. In the event the PWR_GD#signal is present (low) and appropriate software asserts the UNLATCH#signal (low), then the output of AND gate U37A goes high and transistorQ15 is turned “on” via the voltage applied to its base across thedivider network of resistors R271 and R273. With transistor Q15 on, thealways-on “standby” voltage from the main power supply provided at V3SB(3.3 volts) is provided to the base of transistor Q14 through biasresistors R264 and R265, whereupon current may flow through transistorQ14 and through the solenoid 542 to ground.

The current comes in two levels, an “activation” current and a “holding”current. In this regard, note that the circuit 600 includes a pair ofrelatively large, low-leakage capacitors C402, C403 which are charged tocapacity during normal operation by the main power supply V3SB through acurrent limiting resistor R263. When transistor Q14 is turned on, the“activation” current needed to actuate the solenoid 542 is provided bythe rapid discharge of the capacitors C402, C403. Next, after thecapacitors have discharged, the “holding” current needed to keep thesolenoid energized is provided by the lower current flowing from V3SB,through the current limiting resistor R263.

In the absence of good power, PWR_GD# would not be present and theUNLATCH# signal cannot energize the solenoid 542. The capacitors C402,C402 in the circuit 600, however, offer a unique method to provide foran “emergency” removal of the ICM 100. In the absence of power, theminimal amount of current needed to maintain the charge on thecapacitors C402, C403 is provided by VBATT (3 volts). This is the “clockbattery,” i.e. the 3V Lithium cell used to maintain the real-time clock(RTC) when the ICM is not connected to a source of power.

For emergency removal, a manual unlatch switch SW1 is provided on theICM 100, “across” or in parallel with transistor Q15, and made availableto the user. The manual switch SW! should be somewhat difficult tooperate. For example, the manual unlatch switch SW1 might be closed onlyby inserting a paper clip or other small object through a hole in thefront of the ICM 100. When the manual unlatch switch SW1 is closed,transistor Q14 is turned on as before, and the “activation” currentneeded to open the latch is provided by rapid releasing the energystored in the capacitors C402, C403 through the solenoid 542. Underthese “emergency conditions” however, the “holding” current needed tokeep the solenoid 542 open is provided by VBATT (rather than V3SB) togive the user a brief, but sufficient opportunity to remove the ICM 100.

We claim:
 1. An integrated computer module (ICM) for connection to ahost connector means in a host assembly, the host assembly containing aDC power supply with DC voltage therefrom coupled to the host connectormeans, the host assembly connected to or containing a display, the ICMcomprising: a computing subsystem operable solely when connected to thehost assembly, the computing subsystem further comprising: amicroprocessor; a hard disk drive for storing an operating system; meansfor supporting a main memory array; means for transferring at least aportion of the operating system to the main memory array; means forcoupling the microprocessor to the main memory array for executing theoperating system; means for storing digital display descriptor data in avideo memory array; and a video controller for converting the digitaldisplay descriptor data to a time-based display data stream suitable fordriving the display; module connector means for connecting to the hostconnector means, the module connector including first conductors forcoupling the time-based display data stream to the display via the hostconnector means; second conductors for receiving the DC voltage from theDC voltage supply in the host assembly via the host connector means topower the computing subsystem; and third conductors for exchanging datawith an I/O device via the host connector means, an EMI enclosure forcontaining emissions from the computing subsystem; and a coolingsubsystem including a fan powered by the DC voltage received via thehost connector means for providing sufficient airflow to maintain themicroprocessor within specified thermal limits.
 2. The ICM of claim 1wherein the module connector means comprises one connector and whereinthe first, second and third conductors are contained in the oneconnector.
 3. The ICM of claim 1 wherein the main memory array and thevideo memory array are the same.
 4. The ICM of claim 1 wherein the mainmemory array and the video memory array are separate.
 5. The ICM ofclaim 1 wherein the I/O device is one of a keyboard, a mouse, a serialport, and a parallel port.
 6. The ICM of claim 1 wherein the computingsubsystem further comprises an IDE controller that provides a primaryIDE channel and a secondary IDE channel.
 7. The ICM of claim 6 whereinthe disk drive is an IDE drive and wherein the IDE drive is connected tothe primary IDE channel.
 8. The ICM of claim 6 wherein the primary IDEchannel remains inside of the ICM and wherein the module connector meansfurther comprises fourth conductors corresponding to the secondary IDEchannel for exchanging data with an IDE peripheral contained in orattached to the host assembly via the host connector means.
 9. The ICMof claim 1 wherein the EMI enclosure substantially independentlycontains emissions from the computing subsystem.
 10. The ICM of claim 9wherein the ICM is substantially exposed when connected to the hostconnector means in a host assembly.
 11. The ICM of claim 9 wherein theICM is received in a docking bay in the host assembly.
 12. The ICM ofclaim 1 wherein the EMI enclosure relies at least in part on the hostassembly to contain emissions from the computing subsystem.
 13. The ICMof claim 12 wherein the ICM is received in a docking bay in the hostassembly.